Recently I've noticed that every once and a while (usually when I'm sitting or laying down) I'll feel my stomach pulsating (around my belly button). It doesn't happen 100% when I'm sitting or laying down it's almost like a few second burst and than it goes away. It doesn't hurt but it's a really weird sensation. Is it something I should worry about?

Actually there are a lot of people that can notice their stomach pulse. It is totally normal and I had it myself. I also asked my doctor and he told me that it is nothing to worry about and sometimes it is possible that you will notice it.